1. Field of the Invention
The present invention relates to a structural improvement of submersible cooling pump, more specifically, a submersible cooling pump that varies in the length of its stud set as required, has better structural stability and longer service life, as well as allows the spinning direction of motor, indicated by the rotation of provided orifices, to be observed directly through sight holes on the motor cover.
2. Description of the Prior Art
Submersible cooling pumps structurally consist mainly of a motor set and an impeller set, wherein the impeller set is immersed in a liquid container, and a supporting stud set is provided connecting the motor set with said impeller set; when the motor set operates, its shaft drives the impeller set, whose vanes turn and introduce the liquid from outside into the impeller set through the port in an upper cover and discharge, by centrifugal force, the liquid out, through a duct pipe, to an inlet port in the motor set to be finally discharged, through a passage, out from an outlet port. Such a submersible cooling pump has drawbacks as follows:                1. Its stud set together with the impeller set being in a fixed pattern is unable to change the length to adapt to different depths of the liquid container. It thus necessitates a multiple of submersible cooling pumps of varied sizes ready to meet different demands, increasing the space and costs needed by inventory for vendors.        2. On the blades of the motor set, an “indicator point” in a color (usually white) other than that of the blades is provided for observation on the blades' rotating direction when the motor operates abnormally, to allow the determination of whether the motor rotates in normal or reverse direction. So, to make such an observation requires removing the motor cover, an inconvenient and dangerous operation; besides, to determine the direction of the rotation, it must take a while of observation, somewhat tedious practice, as the indicator point is too small to make an easy determination.        3. Also, in motor casing, the motor cover is provided with heat dissipating holes allowing the heat generated by the motor in its rotation to be dissipated through; but, in previous motor casings, there is no protective structure to prevent dust or chips from entering the pump which cause damages to the parts of the device.        